My eurorack rig is inspired by the Evolver, too; but I'm not trying to capture all of the capabilities of an Evolver, just some of its spirit:
https://www.modulargrid.net/e/racks/view/301144The two Functions and the Kinks are very good at producing sequencer-like evolving patterns, the DSM01 gives it the familiar filter sound, and I'll finish it off with the DSM03, which will bring in one of my favorite Evolver features, tuned feedback. A future annex will bring in a sample-based oscillator (probably an A-112-2), a pair of small sequencers, and a multi-mode filter. It won't be an Evolver, but it will be able to do Evolver-like things; some of them, it will do better.
I saw that the name of your rack references the Waldorf KB37. Are you going to get one? I noticed the Waldorf about a week ago, and really liked the idea. 107HP is kind of a weird size, but it looks like a really cool opportunity to make the synth of your dreams. I've been kicking around the math (both kinds: financial math and HP math) since I saw it.